Dimethyl Terephthalate (DMT), with CAS number 120-61-6, plays a fundamental role as a key intermediate in the synthesis of Pigment Yellow 155 (PY155). This high-performance pigment is highly valued across various industries for its vibrant yellow hue, excellent lightfastness, thermal stability, and resistance to solvents. The journey from DMT to PY155 is a critical chemical process that demands precision and quality control.

The synthesis of PY155 involves several steps, beginning with the diazotization of a precursor derived from terephthalic acid. DMT, being a dimethyl ester of terephthalic acid, serves as the initial aromatic compound. It is often converted into an aminoterephthalate derivative, which then undergoes diazotization to form a diazonium salt. This highly reactive diazonium salt is subsequently coupled with another molecule, typically a bisacetoacetarylide compound, to form the disazo pigment PY155.

The quality of the DMT used directly impacts the yield and purity of the final PY155 pigment. Manufacturers like NINGBO INNO PHARMCHEM CO.,LTD. ensure that DMT meets stringent specifications, including a purity of ≥99.0%, and is supplied as white chunks. This high purity is essential to minimize side reactions and ensure the desired coloristic and performance properties of the pigment.

PY155, synthesized from DMT, offers numerous advantages:

  • High Color Strength: PY155 provides intense yellow coloration.
  • Excellent Lightfastness: It maintains its color integrity under prolonged light exposure.
  • Good Thermal Stability: Suitable for applications involving high processing temperatures, such as in plastics.
  • Solvent Resistance: It resists degradation or migration when exposed to various solvents.

These properties make PY155 ideal for use in automotive coatings, industrial paints, high-end plastics, and printing inks where durability and color consistency are critical. The reliable supply of high-quality DMT from manufacturers like NINGBO INNO PHARMCHEM CO.,LTD. is therefore crucial for industries that depend on the performance characteristics of PY155.

In essence, Dimethyl Terephthalate serves as the foundational chemical for producing one of the most important yellow pigments in the market, highlighting its significance in the broader landscape of chemical intermediates and high-performance colorants.